Bagarius is the main villain from Aero Fighters 3/Sonic Wings 3, and the final boss in the Bermuda Triangle stage route (in the Mars stage route you will face either Gurabura or Soh Takeko). Another space entity bent on destroying humanity, Bagarius appeared suddenly three years after the defeat of Lar. Many reports happened worldwide, all telling about large attacks made by aircrafts and war machines, all who clearly resembled those used on World War II. The outbreak takes a large scale, so Lord River N. White, commanding officer of Project Blue, orders a full scale attack against the enemy forces. But, before they had a chance to strike, Bagarius's forces attacks the hangar where all of Project Blue's fighter planes were kept, forcing Lord River to order the use of old airplanes stored on their underground facility. Project Blue's pilots then follow on the tracks of Bagarius, who seems to be warping the entire world, making it look just like in the time of World War II. Chased through the world by Project Blue's pilots, Bagarius finally shows himself in the Bermuda Triangle, where he fights using a large submarine. Bagarius is defeated, and the world reverts back to it's original state.
The fight against Bagarius takes place underwater, where he uses a purple submarine to fight. As the submarine is wrecked, Bagarius starts using his forces to keep the sub's parts from falling apart. As he cannot hold onto it anymore, he starts fighting by himself. Like the other final bosses from the series, you have a set time to defeat him. However, if you fail to defeat him, you will just get a screen with the boss laughing instead of a bad ending.